Fractional esters of polyoxyalkylated p, p&#39;-dihydroxydiphenyl-dimethyl-methane



Patented Sept. 15, 1953 FRACTIONAL ESTERS OF POLYOXY- ALKYLATED D, D DIHYDROXYDI- PHENYL-DIMETHYL-METHANE Melvin De Groote, University to Petrolite Corporation,

ware

City, Mo., assignor a corporation of Dela- No Drawing. Application December 29, 1950, Serial No. 203,536

7 Claims.

The present invention is concerned with certain new chemical products, compounds, or compositions which have useful application in various arts. It includes methods or procedures for manufacturing said new chemical products, compounds or compositions, as well as the products, compounds, or compositions themselves.

Complementary to the above aspect of the invenrtion herein disclosed is my companion invention concerned with the use of these particular chemical compounds, or products, as demulsifying agents in processes or procedures particularly adapted for preventing, breaking, or resolving emulsions of the water-in-oil type, andparticularly petroleum emulsions. See my co-pending application Serial No. 203,535, filed December 29, 1950.

Said new compositions are fractional esters obtained from a polycarboxy acid and oxypropylated bisphenol A. Such bisphenol A is treated with propylene oxide so the molecular weight, based on the hydroxyl value, is in the range of approximately 1,000 to approximately 5,000. Such oxypropylated derivatives are invariably xylene-soluble and water-insoluble. When the molecular weight, based on the hydroxyl value, is modestly in excess of 1,000, for instance, about 1200 to 1500 and higher, the oxypropylated product is kerosene-soluble. My preference is to use an oxypropylated bisphenol A, which is kerosene-soluble, as an intermediate for combination with polycarboxy acid, as hereinafter described. Such esterification procedure yields fractional esters which serve for the herein described purpose.

As is well known, bisphenol A is a chemical compound having the following formula:

Ii, for convenience, the bisphenol A is indicated thus:

the product obtained by oxypropylation may be indicated thus:

with the proviso that n and n represent whole numbers, which, added together, equal a sum varying from 15 to 80, and the acidic ester chtained by reaction of the polycarboxy acid may be indicated thus:

in which the characters have their previous significance, and n" is a whole number not over 2 and R is the radical of the polycarboxy radical /O0OH ooornfl and preferably, free from any radicals having more than 8 uninterrupted carbon atoms in a single group, and with the further proviso that the parent diol, prior to esterification, be preferably kerosene-soluble.

Attention is directed to the co-pending application of C. M. Blair, Jr., Serial No. 70,811, filed January 13, 1949, in which there is described, among other things, a process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of an esterification product of a dicarboxylic acid and a polyalkylene glycol, in which the ratio of equivalents of polybasic acid to equivalents of polyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3 carbon atoms, and in which the molecular weight of the product is between 1,500 to 4,000.

Similarly, there have been used esters of dicarboxy acids and polypropylene glycols, in which 2 moles of the dioarboxy acid ester have been reacted with one mole of a polypropylene glycol having a molecular weight, for example, of 2,000 so as to form an acidic fractional ester. Subsequent examination of what is said herein, in comparison with the previous example, as well as the hereto appended claims, will show the line of delineation between such somewhat comparable compounds. Of greater significance, however, is what is said subsequently in regard to the structure of the parent diol, as compared to polypropylene glycols whose molecular weights may vary from 1,000 to 2,000.

In the instant application the initial starting material, i. e., bisphenol A, is water-insoluble.

Numerous Water-insoluble compounds susceptible to oxyalkylation, and particularly to oxyethylation, have been oxyethylated so as to produce effective surface-active agents, which, in some instances, at least have also had at least modest demulsifying property. Reference is made to similar monomeric compounds having a hydrophobe group containing, for example, 8 to 32 carbon atoms and a reactive hydrogen atom, such as the usual acids, alcohols, alkylated phenols,

amines, amides, etc. In such instances, invariably the approach was to introduce a counterbalancing effect by means of the addition of a hydrophile group, particularly ethylene oxide, or, in some instances, glycide, or perhaps a mixture of both hydrophile groups and hydrophobe groups, as, for example, in the introduction of propylene oxide along with ethylene oxide. In another type of material, a polymeric material such as a resin, has been sub-tested to reaction with an alkylene oxide including propylene oxide. In such instances, certain derivatives obtained from polycarboxy acids have been employed.

Obviously, thousands and thousands of combinations, starting with hundreds of initial waterinsoluble materials, are possible. Exploration of a large number of raw materials has yielded a few which appear to be commercially practical and competitive with available dernulsifying agents. Bisphenol A happens to be one such compound. On the other hand, a somewhat closely comparable compound, p-p bisphenol having the following structure:

.does not seem to yield analogous derivatives of nearly the effectiveness of bisphenol A. The reason or reasons for this difference, is obviously obscure and merely a matter of speculation.

Exhaustive oxypropylation renders a watersoluble material water-insoluble. Similarly, it renders .a kerosene-insoluble material kerosenesoluble; for instance, reference has been made to the fact that this is true, ,for example, using polypropylene glycol 2000. Actually, it is true with polypropylene glycol having lower molecular weights than 2000. These materials are obtained by the oxypropylation of a water-soluble kerosene-insoluble material, 1. e., either water or propylene glycol.

Just why certain different materials which are water-insoluble to start with, and. which presumably are renderedmore water-insoluble by exhaustive oxypropylation (if such expression 4 more water-insoluble has significance), can be converted into a valuable surface-active agent, and particularly a valuable demulsifying agent, by reaction with a polycarboxy acid which does not particularly affect the solubility one way or the otherdepending upon the selection of the acidis unexplainable.

Although the herein described products have a number of industrial applications, the are of particular value for resolving petroleum emulsions of the water-in-oil type, that are of particular value for resolving petroleum emulsions of the water-in-oil type, that are commonly referred to as cut oil, roily oil, emulsified oil," etc, and which. comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. This specific application is described and claimed in our .co-pending application Serial No. 203,535, filed December 29, 1950.

The new products are useful as wetting, deter gent and leveling agents in the laundry, textile and dyeing industries; as wetting agents and detergents in the acid washing of building stone and brick; as Wetting agents and spreaders in the application of asphalt in road building and the like; as a flotation reagent in the flotation separation of various aqueous suspensions containing negatively charged particles, such as sewage, coal washing Waste water, and various trade wastes and the like; as germicides, insecticides, emulsifying agents, as, for example, for cosmetics, spray oils, water-repellent textile finishes; as lubricants, etc.

For convenience, what is said hereinafter will be divided into three parts:

Part 1 is concerned with the cxypropylation derivativesof .bisphenol A;

Part 2 ,is concerned with the preparation of esters from the aforementioned diols or dihydroxylated compounds; and

Part 3 is concerned with certain derivatives which can be-obtained from the diols of the type aforementioned.

PART 1 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, or large scale-size, is not, as a rule, designed for a particular alkyleneoxide. Invariably, and

inevitably, however, or particularly in the case of laboratory equipment and pilot plant size, the design is such as to use any of the customarily available alkylene oxide, 1. e., ethylene oxide, propylene oxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted. at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as, for example, to C. Under such circumstances, the pressure will be lessthan 30 pounds per square inch, unless some special procedure is employed, as is sometimes the case, to wit, keeping an at mosphere of inert gas such as nitrogen in the vessel during the. reaction. Such low-temperature low-reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664, to H- R. Fife et al., dated Septemher '7, 194 8. Lowtemperature low pressure oxypropylations are particularly desirable where the compound being subjected to oxy-propylation contains one, two, or three points of reaction only, such as monohydric alcohols, glycols and triols.

Since low-pressure low-temperature low-ream tion-speed oxypropylations require considerable time, for instance, 1 to 7, days of 24 hours each to complete the reaction, they are conducted, as a. rule, whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features:

(a) A solenoid-controlled valve which shuts off the propylene oxide in event that the term perature gets outside a predetermined and set range, for instance, 95 to 120 0.; and

(b) Another solenoid valve which shuts off the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as to pounds.

Otherwise, the equipment is substantially the same as is commonly employed for this purpose Where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances, such automatic controls are not necessarily used.

Thus, in preparing the various examples, I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylaticn, whether it be oxypropylation or oxyethylation. With certain obvious changes, the equipment can be used also to permit oxyalkylation involving the use of glycide where no pressure is involved, except the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out, the method of using propylene oxide is the same as ethylene oxide. This point is emplasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation, of the c-Xyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure was employed. In this procedure the autoclave was a conventional autoclave made of stainl ss steel having a capacity of approximately 15 gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes, unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operating at speeds from R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide,

to the bottom of the autoclave; along with suit able devices for both cooling and heating the autoclave, such as a cooling jacket, and preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, of course, in essence, small-scale replicas of the usual conventional autoclave used in oxyalkylation procedues. In some instances, in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 /2 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved by the use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gal- In some lon, or somewhat in excess thereof. instances, a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an adjuster tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about pounds was used in connection with the 15gallon autoclave.

Other conventional equipment consists, of course, of the rupture disc, pressure auge, sight feed glass, thermometer, connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used of course, such as safety glass, protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls, which shut off the propylene oxide in event tem= perature of reaction passes out of the predetermined range, or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform, in that the reaction temperature was held within a few degrees of any selected point, for instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds within a 5-pound variation one way or the other, but might drop in practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days (72 hours), for completion of the final member of a series. In some instances, the re-= action may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned. The minimum time recorded was about a 4 hour period in a single step. Reactions indicated as being complete in 10 hours may have been complete in a lesser period of time in light of the automatic equip ment employed. This applies also where the reactions were complete in a shorter period of time, for instance, a to 5 hours. In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the propylene oxide, if fed continuously, would be added at a rate so that the predetermined amount would react within the first 15 hours of the 24-hour period or two-thirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop, the predetermined amount of oxide would still be added, in most instances, well within the predetermined time period. Sometimes where the addition was a comparatively small amount in a 10-hour period, there would be an unquestionable speeding up of the reaction, by simply repeating the examples and using 2, 3, or 4 hours instead of 5 hours.

When operating at a comparatively high temperature, for instance, between to 200 C., an unreacted alkylene oxide such as propylene oxide, makes its presence felt in the increase in pressure, or the consistency of a higher pressure. However, at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted, there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this amount of oxide.

possibility; if need be, a sample must be withdrawn and examined for unreacted propylene oxide. :One obvious procedure, of course, is to oxypropylate at a moderately higher temperature, for instance, at 140 to 150 C. Unreacted oxideafiects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time. required to add a given One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely,

the lower the molecular weight, the faster the reaction takes place. For this reason, sometimes atleast, increasingly the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has ia'comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as ,a week or ten days time may elapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a, number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction, the scale movement through a time operating device was set for eitherone to two hours, so that reaction continued for 1 to 3 hours after the final addition of the last propylene-oxide, and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size auto claves, to wit, on semi-pilot plant or pilot plant size, as well as on large scale size. This final stirring period is intended to avoid the .presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow, continuous run which was shut off in case the lpressure'passed a predetermined point, as previously set out. All thepoints of design, construction, etc., were conventional including the gauges, check valves and entire equipment. As far as I am aware at least two firms, and possibly three, specialize in autoclave equipment such as I have employed in the laboratory, and are prepared to furnish equipment of this same kind. Similarly, pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving ethyleneoxide, glycide, propylene oxide, etc., should notbe conducted except in equipment specifically designed for the purpose.

Example 1a.

The starting material was a commercial grade of bisphenol A. The particular autoclave employed was one having a capacity of gallons or on the average of 120 gallons of reaction mass. The speed of the stirrer could be varied from 150 to 350 R. P. M. Approximately 7.25 pounds of bisphenol A were charged into the autoclave along with .75 .pound of caustic soda. The caustic soda was finely powdered and so was the bisphenol A. 4, pounds of xylene were added. so as to produce a slurry. Needless to say, any other convenient inert solvent could have been used instead of xylene. The reaction .pot was flushed out with nitrogen. The autoclave was sealed and theautomatic devices adjusted for injecting 55.5 pounds of propylene oxide in a little less than 5 hours. The .pressure was set for a maximum of 35 pounds per square inch. This meant that the bulk of the reaction could take place, and probably did take place, at a lower pressure. The comparatively low pressure was the result of the fact that considerable catalyst was present and also the reaction time was :fairly long. The propylene oxide was added comparativelyslowly and more important, the selected temperature was about 220 to 225 F. (slightly higher than the boiling point of water). The. initial introduction of propylene oxide was not started until the heating devices had raised the temperature to just a trifle above the boiling point of water. At the completion of the reaction a sample was taken and oxypropylation proceeded, as described in Example 211, following.

Example 2a 59.68 pounds of the reaction mass identified as Example la, preceding, and 3.54 pounds of solvent as an ingredient, were .permitted to remain in the reaction vessel. Without the addition of any more catalyst, 30.75 pounds of propylene oxide were added. The oxypropylation was conducted in substantiall the same manner in regard to pressure and temperature as in Example 1a, preceding, except that the reaction time was slightly longer, i. e., 5 hours instead of 4 /2 hours. At the end of the reaction period, part of the reaction mass was withdrawn and employed as a sample, and oxypropylation was continued with the remainder of the reaction mass as described in Example. 3a, following.

Example 3'a 59.6 pounds of reaction mass identified as Example 2a., preceding, and containing 2.34 pounds of solvent, were permitted to remain in the reaction vessel. No addition of catalyst was made. 15.5 pounds of propylene oxide were introduced in this third stage. The time period was the same as in Example 211, preceding, to wit, 5 hours. The conditions of temperature and pressure were substantially the same as in Example In, preceding. After the completion of the reaction, part of the reaction mass was withdrawn and the remainder subjected to further oxypropylation, as described in Example 40., following.

Example 4a 67.35 .pounds of the reaction mass identified as Example 3a, preceding, and containing 2.11 pounds of solvent, were permitted to remain in the autoclave. Without adding any more catalyst this reaction mass was subjected to further oxypropylation in the same manner as in the preceding examples. 27 pounds of propylene oxide were added in the same period of time as in the previous example, i. e., 5 hours. Conditions in regard to temperature and pressure were substantially the same as in Example 1a, preceding. At the end of the reaction period, part of the sample was withdrawn and the remainder of the reaction mass was subjected to further oxypropylation, as described in Example 5a, following.

Example 4a, preceding, and containing 1.31 pounds of solvent were subjected to a final oxypropylation step. The amount'of propylene oxide added was 27.38 pounds. No additional catalyst was employed. The conditions of reaction with regard to temperature and pressure were substantially the same as in Example la, preceding, and the time required to add the oxide was 5 hours.

In this particular series of examples the oxypropylation was stopped at this stage. In other series I have continued the oxypropylation so that the theoretical molecular weight was approximately 9,000-10,000 and the hydroxyl molecular weight ranged from 6,000 to 7,000. Other weights, of course, are obtainable, using the same procedure.

Needless to say, the procedure employed to produce oxypropylated derivatives can be employed also to produce oxyethylated derivatives and oxybutylated derivatives of the kind previously described. Such derivatives obtained by treating bisphenol A with 1 to moles of butylene oxide, or a mixture of the two, can then be subjected to oxypropylation in the same manner as illustrated by previous examples so as to yield products having the same molecular weight characteristics and the same solubility or emulsifiability in kerosene.

What is said herein is presented in tabular form in Table I, immediately following, with some added information as to molecular weight and as to solubility of the reaction product in water, xylene and kerosene.

In the above formulas the large X is obviously not intended to signify anything except the central part of a large molecule, Whereas, as far as a speculative explanation is concerned, one need onl consider the terminal radicals, as shown. Such suggestion is of interest only, because it may be a possible explanation of how an increase in hydroxyl value does take place which could be interpreted as a decrease in molecular TABLE I Composition before Composition at end Max Max. pres. Time BPA Oxide Cata- Theo. BPA Oxide Gatafi k hrs.

amt. amt. lyst, mol. amt. amt. lyst, lbs. lbs. lbs. wt. lbs. lbs. lbs.

7. o. 75 2, 070 7. 25 55. o. 75 220-225 25 4% e. 42 49. 0e 66 a, 120 6. 42 79. e1 as 220-225 35 5 4. 24 52. 5s .44 3, 890 4. 24 as. 08 44 220-225 5 3.80 51. 05 .39 5, 500 3. 80 88.05 .39 220-225 35 5 2. 3s 54. so 24 s, 145 2. as 82.07 24 220-225 35 5 TABLE II weight. This matter is considered subsequently in the final paragraphs of the next part, i. e., M W by Solubility P t 2 so The final products at the end of the oxypropyl- H20 Xylene Kerosene ation step, were somewhat viscous liquids, more viscous than ordinary polypropylene glycols, with Insotlilgblenfl gagg a slight amber tint. This color, of course, could 1:830 :::do:::: Do. be removed, if desired, by means of bleaching 5 358 :--:gg:-:: E3: 56 clays, filtering chars, or the like. The products were slightly alkaline, due to the residual caustic Ordinarily in the initial oxypropylation of a simple compound such as ethylene glycol or propylene glycol, the hydroxyl molecular weight is apt to approximate the theoretical molecular weight, based on completeness of reaction, if oxypropylation is conducted slowly and at a comparatively low temperature, as described. In this instance, however, this does not seem to follow, as it is noted in the preceding table that at the point where the theoretical molecular weight is approximately 2,000, the hydroxyl molecular weight is only about one-half this amount. This generalization does not necessarily apply where there are more hydroxyls present, and in the present instance, the results are somewhat peculiar when compared with simple dihydroxylated materials, as described, or with phenols.

The fact that such pronounced variation takes placev between hydroxyl molecular weight and soda. The residual basicity due to the catalyst would be the same if sodium methylate had been employed.

Needless to say, there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular Weight, based on a statistical average, is greater than the molecular weight calculated by usual methods, on basis of acetyl or hydroxyl value. This is true even in the case of a normal run of the kind noted previously.

Actually,

there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances, the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any other procedure,

subject to the above limitations, and'especially in the higher molecular weight range. If any difficulty is encountered in the manufacture of the esters as described in Part 2, the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a matter of common knowledge and requires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

PART 2 As previously pointed out, the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately peceding, and polycarboxyl acids, particularly dicarboxy acids such as adipic acid, phthalic acid, or-anhydride, succinic acid, diglycollic acid, sebacic acid, azeleic acids, aconitic acid, maleic acid or anhydride, citraconic acid.

carboxy fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any equivalents. My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acidsand glycols or other hydroxylated compounds is well known. Needless to say, be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose of economy, it is customary touse either the acid or the anhydride. A conventional pro-. cedure is employed. On a laboratory scale one canemploy a resin pot of the kind describedin U. S. Patent No. 2,499,370, dated March '7, 1950, to De Groote and Keiser, and particularly with one more opening to permit the use of a porous spreader, if hydrochloric acid gas is to be used as a catalyst. Such device or. absorption spreader consists of minuteAlundum thimbles which are connected to a glass tube. One canadd a 's'ul fonic acid such as para-toluene sulfonic acid as a catalyst. There is some objection to this, because in some instances, there is some evidence that this acid catalyst tends to decompose or rearrange heat-oxypropyla'ted compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as di'glycollic acid, which is strongly acidic, there is no need to add anycatalyst. The use of hydrochloric gas has one advantage over para-toluene sulfonic acid, and that is, that at the end of the reaction, it can be removed by flushing out with nitrogen, whereas, there is no reasonably convenient means available of removing the para-toluene sulfonic acid or other sulfonic acid employed. If hydrochloric acid is employed, one need only pass the gas through at an exceedingly slow rate, so as to keep the reaction mass acidic. Only a trace of'acid need be present. I have employed hydrochloric acid gas or the aqueous acid itself to eliminate the initial basic material. My preference, howother obvious various compounds may 1'2 ever, is to use no catalyst whatsoever and to insure complete dryness of the diol, as described in the .final procedure just preceding Table III.

The products obtained in Part 1, preceding, 7 may contain a basic catalyst. As a general procedure, I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowedto stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation steps. This, preliminary step can be carried out in the flask to be used for esterification. If there is any further deposi-.

tion of sodium chloride during the reflux stage, needless to say, a second filtration may be re quired. In any event, the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 1 is then diluted further with suflicient xylene decalin, petroleum solvent, or the like, so that onehas obtained approximately a 65% solution. To this solution there is added a polycarboxylated reactant, as previously described, such as phthalic anhydride, succinic acid, or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is com.- plete, as indicated by elimination of water or drop in carboxylvalue. Needless to say, if one produces a half-ester from an anhydride such-as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedure are conventional and have been so thoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example,- the oxyalkylation can be conducted inabsence of a solvent or the solvent removed afteroxypropylation. Such oxypropylation end'prode not can then be acidified with just enough conride, but in any event, is perfectly acceptablefor esterification in the manner described.

Itis tobe pointed out that the products here described are not polyesters in the sense that there is aplurality of both diol radicalsand acid radicals; the product is characterized byhaving. only. one diol radical.

In some; instances, and in fact, in many instances, I have found that iii-spite of the dehydration methods employed above, a mere trace of water. still comes through, and thatthis mere trace of water certainly interferes with theacetyl orhydroxyl value determination, at least when a number of conventional procedures areused and may retard esterification, particularly Where there isno sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred touse the following procedure: I have employed about .200 grams of'the diol compound, as described in Part 1, preceding; I have added about fidgrams of benzene, and then refluxed 13 this mixture in the glass resin pot, using a phaseseparating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood of 130 to possibly 150 C. When all this water or moisture has been removed, I also withdraw approximately 20 grams or a little less benzene and then add the required amount of the carboxy reactant 14 solvent, such as decalin or an alkylated decalin" which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

In the appended table Solvent #7-3, which appears in all instances, is a mixture of 7 volumes of the aromatic petroleum solvent previously described and 3 volumes of benzene. This was used,

and also abou 150 rams of a high boiling aro- 10 or a similar mixture, in the manner previously matic petroleum solvent. These solvents are sold described. In a large number of similar examples by v ri u oil r fi ri n as f r a l n decalin has been used, but it is my preference to efiect, act as if they werealmost completel y use the above mentioned mixture, and particumatic in character. Typical d1st1llat1on data m layly t t prenminary step of removing ,11 the part cular type I have mp and found 15 the water. If one does not intend to remove the Very Satlsfactory 15 the followmg: solvent, my preference is to use the petroleum I. B. P., 142 C. 50 m1., 242 C, solvent-benzene mixture, although obviously, any 5 m1" C. 5 1 44 C of the other mixtures, such as decalin and xylene, ml., 209 c. 30 ml., 248 C. can be y d. ml., 215 C. 65 m1., 252 C. The data included in the subsequent tables, 20 m1" C 70 1 252 c, 1. e., Tables III and IV, are self-explanatory and ml., 220 C. 75 ml., 260 C. very complete and it is believed no further elabml., 225 C. 80 ml.. 264 C. oration is necessary.

TABLE 111 Mol.wt. Amt. Amt. of Ex. No Ex. No Theo gfgk ggi based of poly. ofaacld of oxg. 124 6 g dmxyl (11:111 hydd.l Polycarboxy reactant carboxy es er cmp 0 ac ua cmp reactant of H. 0. value H. V (grsl) (grs) 1a 2, 070 54.1 101 l, 110 200 Dlglycollic acid 48. 2 1a 2, 070 54. 1 101 1, 110 200 Phthalic anhydride. 53. 3 111 2,070 54.1 101 1,110 200 Maleic 51111 1111115..- 35.3 111 2, 070 54. 1 101 l, 110 205 Gitraconic anhydride 40. 4 la 2, 070 54. 1 101 1, 110 200 Aconitic acid 62. 6 2a 120 35. 0 72.3 1, 552 201 Diglycollic acid 34. 3 2a 3, 120 35. 9 72. 3 1, 552 203 Phthalic auhydridm 38. 5 20 3,120 35.9 72.3 1, 552 202 Ma1eica11hydride 25.4 20 3, 120 35. 9 72. 3 1, 552 201 Citraconic anhydride. 29. l 211 3,120 35.9 72.3 1,552 201 31101111102510 45.3 32 3, 390 23.7 51.2 1, 330 202 Diglycollic 35111... 29.4 30 3, 390 23. 7 51. 2 1, 330 201 Phthalic anhydride. 32. 5 311 3,390 23.7 51.2 1,330 202 Maleic 21111 01155" 21.3 3a 3, 890 28. 7 61. 2 l, 830 201 Aconitic acid 3s. 2 3a 3, 890 28. 7 61. 2 1,830 202 Citraconic anhydrida... 24. 6 4a 5, 500 20. 2 42. 7 2, 620 202 Diglycollic acid 20. 6 4a 5, 500 20. 2 42. 7 2, 520 203 Phthalic anhydride. 23.2 411 5,500 20.2 42.7 2, 520 203 Maleicanhydride 15.2 4a 5, 500 20. 2 42.7 2. 620 203 450111110 acid 27. 0 4a 5, 500 20. 2 42. 7 620 203 Oitraconic anhydride 17.4 511 3,145 13.3 33.1 3, 330 202 131 1 551115 55111 13.1 511 3,145 13.3 33.1 3, 330 202 Phthalic 51111 01103. 17.7 8, 145 13. 8 33. 1 3, 380 202 Maleic anhydride ll. 7 s, 1 5 13. 3 33. 1 3, 330 203 011125111 110 211111 011115... 13. 4 5a 3, 145 13.3 33.1 3,330 202 1150111115 acid 20.3

35 ml., 230 C. m1.. 270 TABLE IV 40 ml., 234 C. ml., 280 C. 45 ml., 237 0. ml., 307 0. Maxi.

Amt. mum Time of After this material 15 added, refluxing 1s cong Solvent 1. s sesteyi. water tinued, and, of course, is at a high temperature, 801d ester fi gaggon filgrtslgn out (115. to wit, about to C. If the carboxy re- .1 of actant is an anhydride, needless to say, no Water of reaction appears; if the carboxy reactant is an 241 148 5% 5 acid water of reaction should appear and should fig 2% l lggg be eliminated at the above reaction temperature. 7 3 245 145 2% None If it is not eliminated, I simply separate out an- Z3 2 N na other 10 to 20 cc. of benzene by means of the 7-3 242 144 4% None phase-separating trap, and thus raise the tem- #3 lg None perature to or 0., or even to 200 0., 27-3 243 134 3 4:7 '7-3 231 173 3/5 4.0 if need be. My preference 1s not to go above H 234 182 7% None 200 C. 7% sg/z None 2/ 4.5 The use of such solvent is extremely satisfac 227 159 1% None tory, provided one does not attempt to remove 7-3 220 220 253 2.3 the solvent subsequently, except by vacuum dis tillatio-n, and provided there is no objection to a 17-3 227 227 e 3.3 little residue. Actually, when these materials Z13 5 g; are used for a purpose such as demulsification, 7-3 220 133 31/ None the solvent might just as well be allowed to re- ,Zj fig}: main. If the solvent is to be removed by d1st1l- 17-3 212 130 3 ,3

lation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive for any'rea'son, reaction does-mot takeiplacezina manner that is acceptable, attention shouldbe directed to the following details:

(a) Recheck the hydroxyl or acetyl value of the oxypropylated primary amines. of the kind specified, and use astoichiometrically equivalent amount of acid;

('b) If the reaction does not proceed with reasonable speed, either raise the temperature indicated or else extend the period of timeup to 12 or'lfi hours, if need be;

(c) If necessary, use of paratoluene sulfonic acid, or some other acid as a catalyst; and

(d)- If the esterification does not produce a clear product, a check should be made to see if an inorganic salt such as sodium chloride or sodium. sulfate. is not precipitating out. Such saltshould be eliminated, at least for exploration experimentation, and can be removed by filtering. 1

Everything else being equal, as the size of the molecule increase and the reactive hydroxylradical represents a smaller fraction of the entire molecule, more diificulty is involved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperatures and long time of reaction, there are formed certain compounds whose compositions are still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been made as to the nature of these compounds, such as being cyclic polymers of propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, i. e., of an aldehyde, ketone, or allyl alcohol. In some instances, an attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant, for the reason that apparently under conditions of reaction less re.- aotive hydroxyl radicals are present than indicated by the hydroxyl value. Under such circumstances, there is simply a residue of the carboxylic reactant which can be removed by filtration, or, if desired, the esterification procedure can be repeated, using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value by conventional procedure leaves much to be desired, due either to the cogeneric materials previously referred to, or, for that matter, the presence of any inorganic salts or propylene oxide. Obviously, this oxide should 'be eliminated.

The solvent employed, if any, can be removed from the finished ester by distillation, and particularly vacuum distillation. The final products or liquids are generally from almost water white or pale straw to a light amberin color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the like, color is not a factor and decolorization isnot justified.

In the above instances I have permitted the solvents to remain present in. the final reaction mass. In other instances, I have followed the same procedure, using decalin or a mixture of decalin or benzene in the same manner and ultimately removed all the solvents by vacuum distillation.

PART 3 One need not point out the products obtained as: intermediates, 1. e-.,. the oxypropylation prodnote, can be. subjected to a number of other reactions which change the terminal groups, as, for example, reaction of ethylene oxide, butylene oxide, glycide, epichlorohydrin, etc. Such products still having residual hydroxyl radicals can again be esterified with the same polyoarboxy acidsdescribed in Part 2 to yield acidic esters, which, in turn, are suitable as demulsifying agents.

Furthermore, such hydroxylated compounds obtained from the polyoxypropylated materials described. in Part 2, or, for that matter, the very sameoxypropylated compounds described in Part.

2 without further reaction, can be treated with a number of reactive materials, such as dimethyl sulfate, sulfuric acid, ethylene imine, etc., to yield entirely new compounds. If treated with maleic anyhdride, monochloroacetic acid, epichlorohydrin, etc., one can prepare further obvious variants by (a) reacting the maleic acid ester after esterification of the residual carboxyl radical with sodium bisulfite So as to give a sulfosucoinate. Furthermore, derivatives having a labile chlorine atom such as those obtained from chloroacetic acid or epichlorohydrin, can bereacted with a tertiary amine to give quaternary ammonium compounds. The acidic esters described herein can, of course, be neutralized with various compounds, so as to alter the water and oilsolubility factors, as, for example, by the use of triethanolamine, cyclohexylamine, etc. All these variations and derivatives have utility in various arts where surface-active materials are of value, and particularly are effective as demulsifiers in the resolution of petroleum emulsions, :as described in Part 3. They may be employed also as break-inducers in the doctor treatment of sour crude, etc.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. Hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which n" has its previous significance.

2. Hydrophile synthetic products; said hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which R is the radical of p,p-dihydroxydiphenyl-dimethyl-methane; n andn are integers with the proviso that n and 11. equal a sum varying from 15 to 80, and R is the radical of a dioar-boxy acid selected from the group consisting 17 of acyclic and isocyclic dicarboxy acids having not more than 8 arbon atoms and composed of carbon, hydrogen and oxygen of the formula:

coon R 3. The product of claim 2, wherein the dicarboxy acid is phthalic acid.

4. The product of claim 2, wherein the dicar- 'boxy acid is maleic acid.

5. The product of claim 2, wherein the dicarboxy acid is succinic acid.

18 6. The product of claim 2, wherein the dicarboxy acid is citraconic acid.

7. The product of claim 2, wherein the dicarboxy acid is diglycollic acid.

MELVIN DE GROOTE.

References Cited in the file of this patent Turner: Condensed Chemical Dictionary (third ed., 1942), p. 125. Reinhold Publishing 0 Corp., New York, N. Y. 

1. HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: 